Recently, a device has been devised in which a predetermined light distribution pattern is formed by reflecting light emitted from a light source toward the front of a vehicle and scanning the region in front of the vehicle with the reflected light. For example, there is known an optical unit which includes a rotary reflector and a plurality of light sources. The rotary reflector rotates in one direction around its rotation axis while reflecting light emitted from a light source. The plurality of light sources is composed of light emitting elements. The rotary reflector is provided with a reflecting surface such that the light of the light sources reflected by the rotary reflector rotating forms a desired light distribution pattern. The plurality of light sources is arranged such that the lights emitted from the light sources are reflected at different position of the reflecting surface (see, Patent Document 1).
Patent Document 1: JP 2015-26628 (A)
However, when scanning a wide range with the light reflected by the rotary reflector, a decrease in the maximum luminous intensity and deterioration in the image forming property are liable to occur. Therefore, in the above-described optical unit, a diffusing LED unit for realizing diffused light to irradiate a wide range is provided, apart from a condensing LED unit for realizing strong condensing on the front side in a travelling direction. Further, light emitted from the condensing LED unit is reflected at a first position of the rotary reflector, and then, is projected forward through a first projection lens. In addition, light emitted from the diffusing LED unit is reflected at a second position of the rotary reflector, and then, is projected forward through a second projection lens. Therefore, a plurality of projection lenses is required, and the entire unit tends to be large.